Notes:

Boost has an option in “Settings-Data Saving” to set the preferred quality for videos (Prefer lower size, Prefer best quality). This setting affects sources that provide different version of videos, like gfycat, giphy, streamable and reddit videos. Reddit videos provides qualities from 240p to 1080p HD. The 240p version is crap, and the 1080p may take some time to load. That’s why I’ve added an additional setting for reddit videos to set the mimimum and maximum quality. That way you can have “Prefer lower size” and set 480p as the lowest version, or “Prefer best quality” but limited to 720p instead of 1080p.